This is his M.O. about just every opinion of his. He's got his view and it's got to be the best one around; he won't accept different points of view and will get passive agressive if you try to discuss politely. I have never seen him concede a point or agree with an oposing argument once his opinion is set. It's like a bull or a tunnel vision, it borders obsession to me.
That said, he looks like a pretty nice guy - albeit a little naive at times, but that's not necessarily bad - and, if you disagree with him, the best course of action is ignoring him, there's no such thing as convincing him. In other words, just try not to oppose or argue.